#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
int func(char* str, int len)
{
	char* left = str;
	char* right = str + len - 1;
	while (left < right)
	{
		if (*left == *right)
		{
			left++; right--;
		}
		else
		{
			return 0;
		}
	}
	return 1;
}
int main()
{
	char arr[30] = { 0 }; //aceca
	while (scanf("%s", arr)!=EOF)
	{
		int len = strlen(arr);
		int i=func(arr, len);
		if (i == 1)
		{
			printf("yes\n");
		}
		else
		{
			printf("no\n");
		}
	}


	return 0;
}